Ultrasmall LiS-Carbon Nanotube Nanocomposites for High-Rate All-Solid-State Lithium-Sulfur Batteries.

Due to the intrinsic poor ionic/electronic conductivities of LiS, it is a great challenge to realize high-rate all-solid-state lithium-sulfur batteries (ASSLSBs) with long cyclic performance. Herein, ultrasmall LiS (∼15 nm) is evenly deposited on a carbon nanotube (CNT) a facile liquid-phase method to address these issues. The unique structure of the LiS deposited on a CNT composite cathode can improve ionic/electronic conductivities of LiS effectively and relieve the generated internal stress/strain during cycling. Specifically, the resultant Li/75%LiS-24%PS-1%PO/LiGePS/LiS-53%CNT ASSLSBs show a reversible capacity of 651.4 mAh g under 1.0C at 60 °C after 300 cycles and even at a much higher cathode load of 5.08 mg cm, a high discharge capacity of 556 mAh g can still be obtained under 0.1C after 20 cycles. The outstanding electrochemical performances are also attributed to the high diffusion coefficient of LiS-53%CNT, which is 39 times that of pristine LiS. This work presents an efficient procedure to design cathode materials with high ionic/electronic conductivities and paves the way for the successful commercialization of high-rate ASSLSBs.